1. Field of the Invention:
The present invention relates to electrical terminals adapted for mounting in a hole in a circuit board, and particularly relates to such terminals that are to be mounted in a plated hole in a circuit board and subsequently soldered to establish an electrical connection between the terminal and conductive paths on the circuit board connected with the plated hole in the board. More particularly, the invention relates to an electrical terminal including a quantity of solder applied to the terminal which may be flowed by heating to establish a permanent electrical connection between the terminal and a plated hole in a circuit board in which the terminal is mounted.
2. Description of the Prior Art:
Electrical terminals including a quantity of discrete and continuous solder wire are described in U.S. Pat. Nos. 3,351,704 and 3,705,256, respectively. A bus bar having a plurality of apertures with solder preforms retained in the apertures is described in U.S. Pat. No. 3,744,129. A circuit board pin is then inserted in a hole in the solder preform in the aperture in the bus bar and the bus bar and pin are heated to flow the solder and establish a permanent electrical connection.
An electrical terminal including a flow-deposited quantity of solder or band of solder adhered to a selected portion of the terminal is described in U.S. Pat. No. 3,915,546. The solder layer or band described in this patent is selectively applied to a mounting portion of a circuit board pin for insertion in a plated hole, and the solder is reflowed when the pin is inserted in a plated circuit board hole to establish a permanent electrical connection between the terminal and plated hole.
The terminal structure including a band of solder applied to the mounting portion is particularly useful when the terminal is a circuit board pin having a wire wrap tail at one end and a pressure contact at the other end. The band of solder may be reflowed after the terminal is inserted in a circuit board hole without contaminating the wire wrap tail or pressure contacts thus eliminating masking and expensive cleaning of either the wire wrap tail or contacts, which would be required if the soldering had been effected by a dip or wave soldering operation.
However, the selective application of the solder band requires an additional manufacturing operation after die stamping of the electrical terminal and expensive and complex manufacturing equipment for carrying out such operations. Additionally, operations are required on such terminals to reduce the force required to insert the solder striped contacts into plated holes in a circuit board and to reduce the damage to the plated hole caused by frictionally interfitting the solder striped contacts therein. Additionally, the quantity of solder that can be adhered to the mounting portion of such a terminal is limited by the requirement that the solder striped contact must fit in a standard size hole in a circuit board.